摘要 |
A beam of x-rays is directed into a travelling product such as paper having a constituent such as ash made up of components such as clay, chalk and titanium dioxide. The x-rays from the product produce a response to a detected spectrum wherein the intensities of the rays are so distributed as a function of energy that the average effective absorption coefficients for the components are substantially equalised, so that the response will be indicative of the constituent and comparatively unaffected by the relative amounts of the components. |